1. Field of the Invention
The present invention relates to a method for polishing bodies of vehicles, particularly of automobiles, and an apparatus for carrying out the method.
2. Description of the Prior Art
A vehicle polishing method which is conventionally known, for example, from U.S. Pat. No. 4,622,246, comprises a first polishing step of forwardly or backwardly moving a portal or gate-type travel frame travellable forwardly and backwardly over a stationary vehicle to polish the body surface of the vehicle by a rotary brush or brushes mounted on the travel frame during such movement while applying a primary treating agent containing an anionic surfactant in the foamy form onto the body surface of the vehicle by a primary treating agent applicator mounted on the travel frame, and a second polishing and rinsing step, following the first polishing step, of backwardly or forwardly moving the travel frame and repolishing the body surface by the rotary brush or brushes during such movement while applying an aqueous wax containing a cationic surfactant onto the body surface by an aqueous wax applicator, and then ejecting fresh water onto the body surface from a rinsing unit mounted on the travel frame to wash away the excessive wax from the body surface.
With the above prior art method, when the cationic surfactant-containing aqueous wax applied at the second polishing step is deposited on the anionic surfactant-containing primary treating agent rubbed on the body surface at the first polishing step, both of the surfactants react together to convert a wax component dissolved in the aqueous wax into an insoluble wax component which is rubbed onto the body surface under the polishing action of the rotary brushes to form a wax film. However, there is a slight time lag from the point of contact of both the surfactants to the point when a satisfactory amount of the insoluble wax component is produced. Meanwhile, an average of travel speeds of the portal travel frame has been recently increased as high as 9 to 10 m/min. (formerly 4 to 5 m/min.) in order to provide a reduction in working time, and there is also a tendency of the polishing time for the body surface to be shortened. Particularly, for the body surface (e.g., the front surface of a bonnet indicated by a character B in FIG. 6b) which is to be polished by the rotary brushes at the beginning of the second polishing step, i.e., at the beginning of contact of the primary treating agent with the aqueous wax, the polishing can be completed when a satisfactory amount of the insoluble wax component is still not produced, resulting in a failure to satisfactorily rub the insoluble wax component onto such surface portion. This leads to a problem that a wax effect on such surface portion is inferior to that on the other surface portion of the vehicle body.